Multicopter aircraft typically include a plurality of horizontally oriented rotors, sometimes referred to as “lift fans,” to provide lift, stability, and control. A flight control system, sometimes referred to as a “flight controller” or “flight computer”, may be provided to translate pilot or other operator input, and/or corrections computed by an onboard computer, e.g., based on sensor data, into forces and moments and/or to further translate such forces and moments into a set of actuator (e.g., lift rotors; propellers; control surfaces, such as ailerons; etc.) and/or associated parameters (e.g., lift fan power, speed, or torque) to provide the required forces and moments.
For example, pilot or other operator inputs may indicate a desired change in the aircraft's speed, direction, and/or orientation, and/or wind or other forces may act on the aircraft, requiring the lift fans and/or other actuators to be used to maintain a desired aircraft attitude (roll/pitch/yaw), speed, and/or altitude.
An aircraft typically is considered to have six degrees of freedom of movement, including forces in the forward/back, side/side, and up/down directions (e.g., Fx, Fy, and Fz) and moments about the longitudinal (roll) axis, the transverse (pitch) axis, and the vertical (yaw) axis (e.g., Mx, My, and Mz). If an aircraft has more actuators than degrees of freedom, it must be determined how the various actuators will be used to act on the aircraft in response to commands received via manual and/or automated controls. For a given set of one or more pilot commands under given circumstances, some combinations of actuators capable of acting on the aircraft to achieve the result indicated by the pilot command(s) may be more effective and/or efficient than others. For example, some may consume more or less power and/or fuel than others, provide a more smooth transition from a current state than others, etc.
Rotors may spin at a high rate and could pose a risk to an occupant of a manned multicopter and/or to equipment housed in a fuselage or other structure comprising the multicopter.